Part of the Shadow of the Mad King event involves using the Candy-Powered Matter Meter to scan suspicious locations and find ghosts. These ghosts then tell a story and give you a Mad Memoirs item. There appear to be six of these in total.

1 Answer
1

The first ghost is next to Magister Tassi, scan Etheric for it to appear.

The sewer under Lions Arch, enter the water south of Yomm’s Mechantile, head north through the sewer and take the first tunnel down, the ghost is right at the back behind all the sunken ships, use a Aqueous scan and talk to it.

Lions Arch again, jump off the Diving Platform and head east towards the ruins, the ghost is on the top floor of a sunken tower, use a Etheric scan and talk to it.

The cemetery in Queensdale, just south of Divinity's Reach, in a tomb on the North wall, use a Gaseous scan and talk to it.

Blackroot Cut in Kessex Hills, there's coffin when scanned a skeleton will appear and point the direction you should go to find the ghost.

Provenic Tombs in Gendarran Fields, fight your way through the tomb. In the room behind the Giant spider do a Gaseous scan, which will reveal two skeletons laughing at a headless ghost, the headless ghost will runaway, follow it and do a gaseous scan to talk to the ghost.

There were lots of other people doing the quest, and if the ghost is already there you can save a candy corn and just talk them without scanning.